C0161

DTC C0161
DTC Descriptor

DTC C0161 11
ABS/TCS Brake Switch Circuit Signal Malfunction

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection

Circuit/System Description
The brake pedal position (BPP) sensor is an input to the instrument panel module (IPM). The IPM then sends a serial data message to the electronic brake control module (EBCM) and other electronic control modules. The BPP sensor is a potentiometer type sensor with a 5-volt reference circuit and a low reference circuit. The IPM supplies the 5-volt reference to the BPP.

Conditions for Running the DTC
C0161 11
^ The ignition is ON.
^ The vehicle speed is greater than 16 km/h (10 mph).
^ The ignition voltage is greater than 8 volts.

C0161 12
^ The ignition is ON.
^ The ignition voltage is greater than 8 volts.

Conditions for Setting the DTC
C0161 11
^ The brake pedal is sensed as applied.
^ The vehicle speed is greater than 40 km/h (25 mph).
^ The vehicles acceleration exceeds 8 km/h per second (5 mph per second).

C0161 12
^ Brake pedal is not applied.
^ Master cylinder pressure is greater than 150 psi.
^ The vehicle speed is greater than 24 km/h (14 mph).
^ The vehicles deceleration exceeds 11.5 km/h per second (7 mph per second).

Action Taken When the DTC Sets
^ The EBCM disables the engine drag control (EDC) / Traction Control System (TCS) / Vehicle Stability Enhancement System (VSES) for the duration of the ignition cycle.
^ The Traction Control indicator turns ON.
^ The driver information center (DIC) displays Service Stability System message.
^ The ABS remains functional.

Conditions for Clearing the DTC
^ The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
^ The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids
The DTC C0161 11 can be set if the vehicle has been driven with the brake applied during acceleration.

Reference Information
Scan Tool Reference
Scan Tool Data List for EBCM

Circuit/System Verification
With the ignition ON, use a scan tool to display DTC's for the instrument panel module (IPM).
^ If DTC C0277 or C0278 are present, go to Diagnostic System Check - Vehicle. Testing and Inspection
^ If no DTC's are present, go to Diagnostic Aids.

Repair Verification
Diagnostic Repair Verification